Synthesis of n,n-bis(2-fluoro-2,2-dinitroethyl)carbamates

ABSTRACT

1. A COMPOUND OF THE FORMULA   (O2N-C(-R1)(-R2)-(CH2)M)2-N-CO-Z-(CH2)N-C(-R3)(-R4)-NO2   WHEREIN R1, R2, R3 AND R4 VARY INDEPENDENTLY AND ARE SELECTED FROM THE GROUP CONSISTING OF F AND NO2, Z IS SELECTED FROM THE GROUP CONSISTING OF O AND NH, AND M AND N VARY INDEPENDENTLY AND ARE INTEGERS OF FROM 1 TO 2.

United States Patent 3,850,978 SYNTHESIS OF N ,N-BIS(2-FLUORO-2,2-DlNITRO- ETHYL) CARBAMATES William H. Gilligan, Washington, D.C., and Mortimer J. Kamlet, Silver Spring, Md., assignors to the United States of America as represented by the Secretary of the Navy 1 No Drawing. Filed Nov. 28, 1973, Ser. No. 419,755

Int. Cl. C07c 125/06 U.S. Cl. 260-482 C 16 Claims ABSTRACT OF THE DISCLOSURE Compounds of the formula R2 is R4 are produced by the following reaction sequence:

lFeCla, H2O

R3 Nordqonnn zn wherein R R R and R vary independently and represent F and N0 Z represents O and NH, and m and n vary independently and are integers from 1 to 2.

, BACKGROUND OF THE INVENTION 1 This invention relates generally to chemical compounds and'their production, and more particularly to carbamates and ureas containing nitroalkyl and fluoroalkyl groups.

In the past it is has been known to produce N,O -bis- (trinitroalkyl) carbamates by condensing a nitro isocyanate with a nitroalkanol. In addition, it has been known to produce N,N'-bis(2,2,2-trinitroethyl) urea by condensing trinitro methane with dimethylolurea. While these bis substituted compounds are useful as explosives, they do not possess the explosive energy that tris substituted compounds do. Unfortunately, these condensation processes of the prior art are capable of producing only the N,O-bis(trim'tro alkyl) carbamates or the N,N'-bis(trinitroethyl) urea, i.e. the processes are not capable of producing either the N,N,O-tris(trinitroalkyl) carbamates or N,N,N'v-tris (trinitroethyl) ureas. Moreover, the N position of thebis carbamates and ureas is so deactivated by the single attached trinitro alkyl group that fura ther substitution is not feasible.

3,850,978 Patented Nov. 26, 1974 SUMMARY OF THE INVENTION wherein R R R and R vary independently and can each be F or N0 Z can be 0 or NH, and m and n are integers which vary independently and can be 1 or 2. These compounds are prepared by a series of reactions culminating in the reaction of compounds of the formula with compounds having either the formula l s NOz-(E-(CHzh-OH under esterifying conditions to produce compounds having the formula wherein R R R R m' and n are as defined above.

3 DESCRIPTION OF THE PREFERRED EMBODIMENTS The synthesis of the compounds of this invention can be wherein R R R and R vary independently and are selected from the group consisting of F and N m and n vary independently and are integers of from 1 to 2. The

first step in the synthesis in the contacting of a secondary amine of Formula I with carbon tetrachloride in the presence of a FeCl catalyst to obtain a tertiary amine of Formula II. The tertiary amine of Formula II is then contacted with water, hydrolyzing the trichloro-methyl group, to obtain the corresponding carbamyl chloride of Formula III.

The carbamyl chlorides of Formula III are useful as intermediates in the synthesis of the explosive carbamates and ureas of this invention.

In final step of the synthesis, a carbamyl chloride of Formula III is contacted with a compound of the formula to obtain an explosive compound of the formula wherein R R R and R vary independently and are selected from the group consisting of F and N0 Z is selected from the group consisting of O and NH, and m and n vary independently and are integers of from 1 to 2. When Z is O, the final step of the synthesis comprises the contacting of a carbamyl chloride of Formula III with an alcohol of Formula IV to obtain a carbamate of Formula V. On the other hand when Z is NH, the final step of the synthesis comprises the contacting of a carbamyl chloride of Formula III with an amine of Formula VI to produce a urea of Formula VIII. Whether Z is O or NH, this final step involves the reaction of a carbamyl chloride with a compound containing an active hydrogen.

N0 groups are necessary for the compounds to be explosives and the fiuoro groups provide improved thermal and or as in the ureas it is preferable that R and R both be F while R and R vary independently and are selected from the group consisting of F and N0 These preferable compounds would, therefore, include carbamates such as Since the 0 position nitro alkyl-or fluoronitro alkyl substitute is added to the carbamate in a separate step, it may be different from the two N,N position nitro alkyl or :guoro nitro alkyl substitutes. Thus, mixed carbamates suc as can be prepared. Similarly, since the N position nitro alkyl or fluoro alkyl substitute is added to the urea in a separate step, it may be different from the two 'N,N position nitro alkyl or fluoronitro alkyl substitutes. Thus, mix ureas such as I etc. can be prepared.

Although the above mixed substituted carbamates and ureas are possible, carbamates and ureas of this invention in which in and 11 both equal l are more preferred because they make more powerful explosives than compounds in which m or n equals 2. Thus the more preferred carbamates of this invention are l and [(NO F C CH NCONHCH CF(NO e 2 )z r-l z CONHC ZCF 2) 2 being the most preferred prom,

The carbamyl chloride of Formula II I ma y be selected from the group consisting of Because F substitutes improve the thermal stability of the compounds,

are preferred. More preferred are the fluoro substituted compounds of Formula III in which m: 1, i.e.

being the most preferred carbamyl chloride.

The following examples are given byway of illustration only and are not to be construed as limiting this invention in any manner:

EXAMPLE I N,N-bis(2-fluoro-2,2-dinitro ethyl) carbamyl chloride To a slurry of 16 g. of anhydrous ferric chloride in 105 ml. of carbon tetrachloride, 52 g. of N,N-bis(2-fluoro- 2,2dinitroethyl)amine was added. The mixture was then refluxed for 48 hours with stirring. Next 4 ml. of water in 10' ml. of tetrahydrofuran was added dropwise to the mixture at the reflux temperature over a period of 40 minutes. Refluxing was then continued for an additional hour. The reaction mixture was then taken up in 100 ml. methylene chloride. The methylene chloride solution was then dried over anhydrous magnesium sulfate, filtered, and evaporated in vacuo, leaving the product as a residue.

EXAMPLE II N,N,O-tris(2-fiuoro-2,2-dinitroethyl) carbamate The residue produced in Example 1 was redissolved in 100 m1. of methylene chloride. To the cooled solution (ice-bath) was added 18 ml. of 2-fluoro-2,2-dinitroethanol. Next, ml. of triethylamine was added to the cooled solution over a period of 40 minutes. The solution was then allowed to warm up to ,room temperature and then refluxed overnight. After the solution had cooled to room temperature, the solution was washed first with dilute hydrochloric acid and thenwith water. Next the solution was dried over anhydrous magnesium sulfate, filtered, and the volatiles were removed in vacuo; leaving a residue. The residue was then recrystallized from ether/hexane and finally recrystallized from to give 42.4 gm. of N,N,O-tris-(2-fiuoro-2,2-dinitroethyl) carbamate; m.p. 63-5".

Analysis. Calculated for C7H6F3N7014. C, 17.92; H,

1.29; F, 12.15; N, 20.90. Found, 17.88; H, 1.15; F,

Although this invention has been described with reference to but a few preferred embodiments, it should be apparent that it is by no means so limited but, within the scope of the appended claims, it may be practiced in a manner other than as described. 1

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A compound of the formula wherein R R R and R vary independently and are selected from the group consisting of F and N0 Z is selected from the group consisting of 0 and NH, and m and n vary independently and are integers of from 1 to 2.

2. A compound according to claim 1 wherein Z is O.

3. A compound according to claim 2 wherein R is F and R is F.

4. A compound according to claim 3 wherein m equals 1 and n equals 1.

5. A compound according to claim 4 wherein the compound is 6. A compound according to claim 1 wherein Z is NH.

7. A compound according to claim 6 wherein R is F and R is F.

8. A compound according to claim 7 wherein m equals 1 and n equals 1.

9. A compound according to claim 8 wherein the compound is [CF(NOz)2CHz]2Nlii-NHCH2CF(NO2)2 10. A compound of the formula wherein R and R vary independently and are selected from the group consisting of F and N0 and m is an integer of from 1 to 2.

11. A compound according to claim 10 wherein R is F.

12. A compound according to claim 11 wherein m equals 1.

13. A compound according to claim 12 wherein the compound is 14. Aprocess for the production of the of claim 1 comprising:

(a) contacting with carbon tetrachloride to obtain R: and contacting with water to obtain and (b) contacting NC C13 NOCla compounds References Cited 20 UNITED, STATES PATENTS 3,644,519 2/1972 Adolph 260-553 R 2,978,491 4/1961 Frankel 260482 c 25 LORRAINE A. WEINBERGER, Primary Examiner P. KILLOS, Assistant Examiner US. Cl. X.R. 

1. A COMPOUND OF THE FORMULA 